Political activity born in abandonment of religion, etc (14)
I believe the answer is:
electioneering
'political activity' is the definition.
(process of fighting elections)
'born in abandonment of religion etc' is the wordplay.
'born' becomes 'nee' ('nee' is 'born' in French).
'in' is an insertion indicator.
'abandonment of' indicates anagramming the letters.
'religion'+'etc'='religionetc'
'religionetc' is an anagram of 'electioring'.
'nee' placed into 'electioring' is 'ELECTIONEERING'.
(Another definition for electioneering that I've seen is " engaged in politics".)